MP4Cam2AVI is a MP4/MOV/M2TS to AVI repackaging tool for digital photo-video cameras, it makes their clips editable in VirtualDub, MovieMaker and other AVI editors. Also it can combine (join) multiple clips from camera into a single AVI movie, preserving audio/video sync.
No video recompression (by default), no quality loss, fast operation (5-20x realtime). No installation needed - just download, unzip and run mp4cam2avi.exe.